Among the base materials for thermobinding interlining, there are distinguished, on the one hand, the textile base materials proper and, on the other hand, the nonwovens. The textile base materials proper are obtained by weaving or knitting yarns, whilst the nonwovens are obtained by constituting and consolidating a web of fibers or filaments.
For making textile base materials intended for interlining fine, light cloth, for example shirts, dresses or light jackets, texturized synthetic yarns have already been used, obtained by the set false twist process. This limitation to fine, light cloths is due to the small volume and to the smooth surface resulting from the slight crimp of the texturized continuous filaments obtained by this technique of texturization. Furthermore, to give such textile base materials the touch necessary for the interlining, it is necessary to subject them to treatments of shrinking and thermofixing after weaving or knitting, in order to reveal the crimp of the filaments.
The effect of such shrinking and thermofixing treatments is to increase the volume of the textile support and thus to modify its touch. This necessitates producing, by weaving or knitting, a textile base material which presents a width 15 to 30% greater than that obtained after the shrinking and thermofixing treatments. It is therefore necessary to employ looms making it possible to work at a greater width.
Moreover, the textile base material thus shrunk presents a residual extensibility which is close to the shrinkage rate. This extensibility may be detrimental to the undeformability of the garment when worn, since the interlining is not in a position to stabilize the garment piece when the latter is itself extensible, for example when it is question of a stitched article.
Furthermore, in the domain of thermobonding interlining, it is desired that the textile base material has a very good covering power, so that the deposits of thermofusible polymer made on the surface of said base material do not penetrate thereinside, such a penetration has for effect locally to rigidify said interlining and consequently the garment piece. With equal interlining weight, the polymer penetrates with greater difficulty as the surface of the base material is closed, i.e. there is a reduced space between the different fibers or filaments which constitute the base material. The more this space is reduced, the more the base material has a great covering power. Structurally, at equal weight, the nonwoven interlining base material has a much greater covering power than the textile base material proper.
However, the nonwoven lacks voluminosity to constitute a thermobonding interlining acceptable in many applications.
It is an object of the present invention to propose a textile base material for thermobonding interlining which presents a covering power similar to that of a nonwoven and which does not present the above-mentioned drawbacks of the textile base material comprising texturized yarns obtained by the set false twist process.